# 使用 Tailwind CSS 制作带动画的加载骨架屏

> 使用 Tailwind CSS 和微光（shimmer）效果构建带动画的加载骨架屏，让你在真实内容加载期间展示占位 UI。

作者 Shodipo Ayomide，发布于 2022年7月18日。网页版本：https://blog.shodipoayomide.com/zh/animated-loading-skeletons-with-tailwind

<div className="grid grid-cols-2 gap-6 sm:grid-cols-3">
  <div>
    
  </div>
  <div>
    
  </div>
  <div className="hidden sm:block">
    
  </div>
</div>

# 骨架屏

- 利用 Tailwind 丰富的工具类，创建一个与即将加载的内容大致相似的骨架。

<div className="space-y-2">
  <div className="flex justify-center rounded-lg bg-rose-100/[1%] p-8 ring-1 ring-inset ring-rose-100/[3%]">
    <div className="w-[200px] space-y-5 rounded-2xl bg-white/5 p-4">
      <div className="h-24 rounded-lg bg-rose-100/10"></div>
      <div className="space-y-3">
        <div className="h-3 w-3/5 rounded-lg bg-rose-100/10"></div>
        <div className="h-3 w-4/5 rounded-lg bg-rose-100/20"></div>
        <div className="h-3 w-2/5 rounded-lg bg-rose-100/20"></div>
      </div>
    </div>
  </div>
  ```html
  <div class="space-y-5 rounded-2xl bg-white/5 p-4">
    <div class="h-24 rounded-lg bg-rose-100/10"></div>
    <div class="space-y-3">
      <div class="h-3 w-3/5 rounded-lg bg-rose-100/10"></div>
      <div class="h-3 w-4/5 rounded-lg bg-rose-100/20"></div>
      <div class="h-3 w-2/5 rounded-lg bg-rose-100/20"></div>
    </div>
  </div>
  ```
</div>

# 渐变遮罩

- 使用 Tailwind 的渐变色标（gradient color stops）创建一个从透明渐变到白色、再渐变回透明的渐变效果。

<div className="space-y-2">
  <div className="flex justify-center rounded-lg bg-rose-100/[1%] p-8 ring-1 ring-inset ring-rose-100/[3%]">
    <div className="w-[200px]">
      <div className="h-48 bg-gradient-to-r from-transparent via-rose-100/20 to-transparent"></div>
    </div>
  </div>
  ```html
  <div
    class="
      [...]
      bg-gradient-to-r from-transparent via-rose-100/10 to-transparent"
  ></div>
  ```
</div>

# 动画

- 在 `tailwind.config.js` 的 extend keyframes 对象中定义一个 CSS 关键帧动画，让元素向右平移 100%。
- 使用 Tailwind 的任意值（arbitrary values）把这个关键帧动画应用到遮罩元素上。

<div className="space-y-2">
  <div className="flex justify-center rounded-lg bg-rose-100/[1%] p-8 ring-1 ring-inset ring-rose-100/[3%]">
    <div className="w-[200px]">
      <div className="relative h-48 -translate-x-full animate-[shimmer_2s_infinite] bg-gradient-to-r from-transparent via-rose-100/20 to-transparent"></div>
    </div>
  </div>
  ```json
  {
    "keyframes": {
      "shimmer": {
        "100%": {
          "transform": "translateX(100%)",
        },
      },
    }
  },
  ```
  ```html
  <div class="[...] -translate-x-full animate-[shimmer_2s_infinite]"></div>
  ```
</div>

# 组合骨架屏与遮罩动画

- 使用 Tailwind 的 `before:` 修饰符，把遮罩添加到骨架屏外层容器的伪元素上。

<div className="space-y-2">
  <div className="flex justify-center rounded-lg bg-rose-100/[1%] p-8 ring-1 ring-inset ring-rose-100/[3%]">
    <div className="w-[200px]">
      <div className="relative space-y-5 rounded-2xl bg-white/5 p-4 before:absolute before:inset-0 before:-translate-x-full before:animate-[shimmer_2s_infinite] before:bg-gradient-to-r before:from-transparent before:via-rose-100/10 before:to-transparent">
        <div className="h-24 rounded-lg bg-rose-100/10"></div>
        <div className="space-y-3">
          <div className="h-3 w-3/5 rounded-lg bg-rose-100/10"></div>
          <div className="h-3 w-4/5 rounded-lg bg-rose-100/20"></div>
          <div className="h-3 w-2/5 rounded-lg bg-rose-100/20"></div>
        </div>
      </div>
    </div>
  </div>
  ```html
  <div
    class="
      [...]
      relative 
      before:absolute before:inset-0
      before:-translate-x-full
      before:animate-[shimmer_2s_infinite]
      before:bg-gradient-to-r
      before:from-transparent before:via-rose-100/10 before:to-transparent"
  >
    [...]
  </div>
  ```
</div>

# 收尾润色

- 当遮罩位于骨架屏之外时将其隐藏。
- 给骨架屏加上阴影。
- 在遮罩顶部添加一条细微的边框，模拟光线反射的效果。
- 你可以用 `isolate` 修复 Safari 在圆角处动画溢出的问题。

<div className="space-y-2">
  <div className="flex justify-center rounded-lg bg-rose-100/[1%] p-8 ring-1 ring-inset ring-rose-100/[3%]">
    <div className="w-[200px]">
      <div className="relative isolate space-y-5 overflow-hidden rounded-2xl bg-white/5 p-4 shadow-xl shadow-black/5 before:absolute before:inset-0 before:-translate-x-full before:animate-[shimmer_2s_infinite] before:border-t before:border-rose-100/10 before:bg-gradient-to-r before:from-transparent before:via-rose-100/10 before:to-transparent">
        <div className="h-24 rounded-lg bg-rose-100/10"></div>
        <div className="space-y-3">
          <div className="h-3 w-3/5 rounded-lg bg-rose-100/10"></div>
          <div className="h-3 w-4/5 rounded-lg bg-rose-100/20"></div>
          <div className="h-3 w-2/5 rounded-lg bg-rose-100/20"></div>
        </div>
      </div>
    </div>
  </div>
  ```html
  <div
    class="
      [...]
      isolate
      overflow-hidden
      shadow-xl shadow-black/5
      before:border-t before:border-rose-100/10"
  >
    [...]
  </div>
  ```
</div>
